Lubrication system for sewing machines



A. C. PETERSON LUBRICATION SYSTEM FOR SEWING MACHINES Dec. 20, 1955 4 Sheets-Sheet 1 Filed May 10, 1952 HV'I'IJNI'OR.

ALBERT C. PETERSON ORNEY Dec. 20, 1955 A. c. PETERSON LUBRICATION SYSTEM FOR SEWING MACHINES 4 Sheets-Sheet 2 V Filed May 10, 1952 ZNVENTOR.

ALBERT C PETERSON T ZKZLQM7 ATTORNEY Dec. 20, 1955 A. c. PETERSON 2,727,430

LUBRICATION SYSTEM FOR SEWING MACHINES Filed May 10, 1952 4 Sheets-Sheet 3 FIGS INVEN TOR.

ALBERT C. PETERSON ATTORNEY Dec. 20, 1955 A. c. PETERSON 2,727,430

LUBRICATION SYSTEM FOR SEWING MACHINES Fil d May 10, 1952 4 Sheets-Sheet 4 Q j %:5 JNVEN TOR.

ALBERT C. PETERSON BY ATTORNEY United States Patent LUBRICATION SYSTEM non SEWING MACHINES Albert C. Peterson, Park Ridge, 111., assignor to Union Special Machine Company, Chicago, 111., a corporation of Illinois Application May 10, 1952, Serial No. 287,176 8 Claims. (Cl. 112-256) The present invention relates to improvements in lubricating systems for sewing machines and has reference more particularly to machines having a circulatory oil system in which excess oil supplied to the parts is collected in a return reservoir in the base of the machine.

It relates especially to the provision of suitable oil cleaning devices in such a system. The invention is herein disclosed as embodied in a flat bed overhanging arm sewing machine of the general type having a group of thread carrying needles mounted on a vertically reciprocating needle bar on the overhanging arm, conventional looper, and work feeding devices mounted in the base. The machine shown is of a type generally employed in the commercial production of garments and the like and is driven at extremely high speed.

In machines of the general type referred to it has been found that the oil distributed to the several operating parts of the machine, and more particularly the oil dis tributed to the looper and the work feeding mechanism adjacent the sewing point, and thereafter returned by gravity to a collection sump or reservoir in the machine base, tends to pick up a very substantial accumulation of lint and dirt which would, if recirculated to the machine, case excess wear and damage to the lubricated parts and bearings. It is the usual practice to collect this dirty oil, which accumulates beneath the looper and feed dog and the associated operating mechanisms, in containers located under the machine and secured either to the machine base or to the sewing table on which the machine is mounted. Such containers must be periodically emptied by the operator, the dirty oil being either disposed of or processed at a remote point for subsequent reuse.

It is a primary object of the invention to provide a simple and efiicient oil cleaning device which is well adapted for use in a machine of the flat bed type for collecting, filtering and returning to the main oil reservoir: 50

the collected surplusage of the oil utilized to lubricate the looper and work feeding mechanisms and other moving parts in the bed of the machine in the region of stitch formation.

It is another object of the invention to provide a compact and at the same time highly efiicient filter unit which is readily removable for cleaning or replacement of parts, and for the more efiicient packaging of the machine for transportation or storage.

With these and other objects in view as may hereinafter appear, the several features of the invention consist in the devices, combinations and arrangement of parts hereinafter described and claimed, which, together with the advantages to be obtained thereby will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a view, partly in front elevation and partly in vertical section, flat bed sewing machine illustrating in a preferred form the several features of the invention;

Fig. 2 is an isometric view on an enlargedscale of a of an overhanging arm multiple needle,

portion of the filter unit which forms an important feature of the invention;

Fig. 3 is a vertical sectional view through the improved filter unit;

Fig. 4 is a detail view, in vertical section, showing the pump gears and their supporting shafts;

Fig. 5 is a vertical sectional view of the gear pump unit mounted in the base and the driving connection from the main crank shaft of the machine;

Fig. 6 is a bottom plan view of the gear pump unit with the bottom plate removed;

.mechanisms and which is Fig. 7 is a bottom plan view of the machine, with the filter unit removed and with a portion of the bottom plate of the gear pump unit broken away; and

Figs. 8, 9, and 10 are views of a flanged collar which is fastened to the upper end of an oil collecting sump and which forms one element of a bayonet lock by means of which the sump is detachably secured to the associated fitting, Fig. 8 being a front view, Fig. 9 a plan view, and Fig. 10 a side view of this part.

Referring to the drawings the invention is shown in a preferred form as embodied in an overhanging arm flat bed sewing machine comprising a base 20, a vertical standard 22 and an overhanging arm 24.

The sewing mechanism of the illustrated machine comprises a group of three thread carrying needles 26 secured to the lower end of a vertically reciprocating needle bar 28 in the overhanging arm 24, and a looper 30 mounted to oscillate with a rocker arm 32 in the base. The machine is also provided with a presser foot 34 and a feed dog 36; the feed dog may be of conventional construction and arranged for four motion movement. A trimming mechanism, not disclosed, may be provided in association with the stitch forming and work feed'mg devices.

The driving mechanism for the machine comprises a main drive shaft 38 horizontally disposed in the base 20 and provided at its outer end with a driving pulley 40. As indicated in Fig. 1 the needle bar 28 is driven from a crank 42 on the shaft 38 through connections which include a vertically extending pitman 43, a rocker arm 44 extending longitudinally of the overhanging arm, and a link 45. Other operating parts, such as cover thread laying means, carried by the overhanging arm, are driven from a crank 46 and a pitman 47. The looper 3i), feed dog 36 and trimming mechanism in the base are driven from a forward extension of the main drive shaft 38 through connections which may be of conventional construction and are not here shown. The general arrangement of the sewing mechanism of the machine, as generally indicated above, being well known in the art is believed to need no further description.

The illustrated machine is provided with an oil lubrication system which includes a main reservoir 48 formed in the base 20 and extending beneath the column 22, and an excess lubricant sump or return reservoir 49 which is disposed in that portion of the base lying directly beneath the sewing instrumentalities of the machine. The reservoirs are separated by a partition 50 generally indicated in Figs. 1 and 3. Oil is distributed from the main reservoir 48 to the various parts of the machine by suitable wicking or other lubricant delivering devices which form no part of the present invention and are not here specifically described. Lubricant is supplied to the various parts of the looper and work feed mechanisms in amounts which are in excess of the amount of lubricant actually consumed in the bearings, the excess being then drained by gravity into the sump or return reservoir 49. Inasmuch as lubrication systems of the type described are well known in the art and form specifically no part of the present invention, no further description thereof is believed necessary.

The oil which is delivered to the looper and work feed subsequently collected in the return reservoir 49, is normally heavily laden with lint and other impurities which render this oil unfit for further use. In accordance with the invention a novel and improved oilcleaning device is provided which reconditions the oil caught in the return reservoir 49 and returns the same to the mainreservoir 48 for recirculation in the machine.

The oil cleaning device of the present inventioncomprises an oil filter unit supported from the under side of the machine base beneath the return oil reservoir 49, a gear pump unit supported within or beneath the main reservoir 48 and arranged to be assembled in the bottom of the base of the machine frame, and a connecting pipe through which oil, reconditioned by the filter unit, is drawn by the pump unit and discharged into the main reservoir 43. The filter unit referred to comprises a depending cylindrically shaped collector or container 54, a filter bag 55 cylindrically shaped and positioned concentrically within container 54, and a cap 56 to which these parts are secured. Container 54 is preferably formed of steel but may beformed of transparent material such as lucite or the like. Filter bag 55 may be formed in any suitable way, as by appropriate stitching operations, from filter cloth or the like. Cap 56 (see Figs. 3 and 7) is fastened by means of screws 58 into a correspondingly shaped aperture in the bottom of the return reservoir 49. The upper portion of the cap is of reduced diameter and fits into a correspondingly reduced portion of the aperture in the base. The upper face of the cap 56 is formed with an annular, upwardly extending flange 60 providing a shouldered recess in which is mounted a filter screen 62. Immediately beneath screen 62 is a small pocket 64 which is preferably filled with a suitable filter medium 65 such as felt or spun fiber. The underside of the cap 56 is formed with a deep annular groove 66 in which is fitted the depending portion of the filter unit including container 54. Oil collected in the return reservoir 49 passes downwardly through the filter screen 62, filter medium 65, through one or more passageways 68 connecting with the annular groove 66, and thence into the container 54. The center portion of the underside of the cap 56 is formed with a conical seat 70 extending upwardly into an oil discharge pocket 72 which is connected with a pipe 74 through which reconditioned oil is withdrawn from the filter unit. The open end of the filter bag 55 is fitted over a plug 76 which is cone shaped at its upper end to fit onto the conical seat 70 and is provided with a central bore 78 connecting with the discharge pocket 72. A withdrawal pipe 80 fitted into the bottom of the plug 76 extends downwardly within the filter bag 55 so that the inlet orifice through which oil is drawn into the pipe is located toward the lower end of the filter bag. The filter bag 55 is maintained in an extended position by means of a spring expander82 consisting of a wire having a loop of the desired circumference at its lower end and a pair of upwardly extending branches terminating at the free end of the wire adjacent the pipe 80, said expander serving to stretch the lower end of the filter bag into its cylindrical shape. The filter bag 55 and plug 76 are held in a sealed relation to the conical seat 72 by means of a spring 86 coiled about the filter bag 55 and plug 76 and seated at its lower end against the bottom of the container 54 and at its upper end against a shoulder 88 formed in the periphery of the plug 76.

The container 54 is detachably secured to the cap 56 by means of a bayonet locking device which consists of a collar 93, see Figs. 8, 9, and 10, formed at its upper edge with three undercut bayonetlocking grooves 92 and an additional cutout 94 to avoid interference with the pipe t and having its lower edge flanged outwardly at 96. The flange provides support fora washer 98 formed of neoprene rubber or the like, and is adapted to engage with the outwardly and upwardly flanged lip of the vessel 54. The bayonet locking collar 90 is permanently fastened to the vessel 54, as for example by brazing. The bayonet locking grooves 92 in the collar are arranged for locking engagement with cooperating pins 100, which are fitted into radial bores in the cap 56 and project inwardly across the annular groove 66.

Filtered and reconditioned oil is drawn from the discharge pocket 72 of the filter unit through the pipe 74 to a gear pump unit which delivers the oil into the main reservoir 48 above the level of the oil contained therein as will be evident particularly from an inspection of Figs. 1 and 7. The pipe 74 is located, for protection, in a groove 104 formed in the bottom of the base 20 of the machine,-but is exteriorly mounted so that it is readily removable from the machine as a unit with the cap 56 and the gear pump unit about to be described. Pipe 74 is preferably provided with a bend, as shown, and adequate clearance is provided between it and the groove to allow for expansion and contraction with changes in temperature. The gear pump unit with which the pipe 74 is connected, as shown in Figs. 4, 5 and 6,-comprises a casing 106, having an outwardly flanged bottom portion 108, which is tightly fitted into a recessed aperture formed in the bottom of the main reservoir 48, and is held in place by machine screws 112. A suitable gasket is provided between the flange 108 and the bottom of the frame while a bottom cover plate 110 for the pump unit is also secured by the screws 112. The gear unit comprises two intermeshing pump gears 114 and116 positioned in a suitable recess in the bottom of casing 106. The gear 116 is mounted to turn on the lower end of a stub shaft 118 while the gear 114 is fixedly mounted on the lower end of a drive shaft 120 journaled in the casing 106 and provided at its upper end with a bevelled gear 122 which meshes with a bevelled gear 124 fastened to the main shaft 38 of the machine. Reconditioned oil is drawn from the filter unit through pipe 74 by the gear pump unit and is forced upwardly by the latter through a passageway 126 in the casing 106 from which it is discharged into the reservoir 48 above the level of oil therein, as indicated in Fig. 1.

The oil cleaning device of the present invention operates in a most eflicient and satisfactory manner to clean;

and to return to active use in the main reservoir all of the surplus oil drained from the looper, work feed and trimming mechanisms which are mounted in the base beneath the throat plate and adjacent portions of the cloth plate of the machine, and which because of this location are subject to excessive accumulations of lint and dirt. During the machine operation, impurity laden oil accumulating in the return reservoir 49 is allowed to drain through the filter screen 62 and filtering medium 65 by gravity aided by the suction action of the gear pump, so that these filtering elements will operate with maximum efliciency in sifting out lint and other impurities. Screen element 62 serves to prevent the filter medium 65 from becoming quickly clogged with these impurities. As the partially reconditioned oil is collected in the container 54, it is drawn by the suction action of the pump through the filter bag 82 into the filter pipe 80, through pipe 74 to the pump gears 114, 116, and is thence discharged through passageway 126 into the reservoir 48.

The filter unit herein illustrated and described as embodying the several features of the invention has the advantage that it is compact, is readily removable for purposes of cleaning or replacement of parts, and is at the same time well adapted to operate with a maximum of efficiency for the removal of impurities from the reconditioned oil. This unit is mounted in an airtight and lubricant tight manner so as to insure the full suction effect on the lubricant which accumulates above the screen 62. The arrangement of the filter elements has been found of particular value in that the filter screen 62, withor without thev addition of a filtering medium 65, will act to remove the lighter and more bulky impurities such as lint, while the arrangement of the container 54 and the filter bag through which the oil is drawn inwardly by the suction of the gear pump, permits denser and finer impurities to be arrested on the outside of the filter bag 55 or to settle out in the bottom of the container. The depending cylindrically shaped filter bag presents a relatively large filtering surface through which the oil may be drawn under a low suction head into the filter pipe within the bag.

The illustrated arrangement of the oil cleaning devices, including the filter unit and the pump unit, is such as to permit these parts to be readily removed for replacement and repair as needed. Removal of the entire assembly, including the filter unit cap 56, the gear pump casing 106 and pipe 74 is readily accomplished by the removal of the screws 58, which releases the cap 56, and by the removal of screws 112 which releases the gear unit casing 106. The container 54, and filter bag 55 may be removed separately when so desired, by simply turning the same to disengage the bayonet locking means above described. It is contemplated that the container 54 will be disconnected from the cap 56 and removed in order to prepare the machine either for transportation or for storage in a flat position on its base.

A preferred embodiment of the described, what is claimed is:

1. A sewing machine having an oil collecting sump, a cap connected with the bottom of the sump, a receptacle detachably secured to and depending from the cap, a filter bag depending from the cap within the receptacle and removable from the cap and said receptacle upon detachment of the latter, said cap having formed therein a filter element receiving recess with a filter element extending across the same and a drainage passageway from the recess through the cap disposed at one side of the axis of said cap and communicating with the receptacle externally of the filter bag, said cap also having an outlet passageway communicating with the filter bag, and a filter tube extending downwardly from said outlet passageway within the filter bag and having the inlet opening thereof disposed adjacent to the lower end of said filter bag.

2. A sewing machine having an oil collecting sump, a cylindrical cap secured into the bottom of the sump and having formed in the upper face thereof a filter element receiving recess which is in open communication with said sump, said cap having a drainage passageway therethrough and having formed on the underside thereof an annular groove communicating with said drainage pas sageway, said cap having also at its underside a centrally disposed conical seat and an outlet passageway communicating with the upper end of said seat, a filter element extending across said recess, a receptacle extending into said groove and detachably secured to and depending from the cap, yielding means efiecting a tight seal between said receptacle and said cap, a filter bag depending within the receptacle and having at its upper end a conical seating element supported against said conical seat, and a discharge tube supported from the conical seating element communicating at its upper end with the outlet passageway and extending downwardly within the filter bag with the inlet opening thereof toward the bottom of the filter bag.

3. A sewing machine having an oil collecting sump, a cap secured to the bottom of the sump and having formed in the upper face thereof a filter element receiving recess which is in open communication with said sump and having a drainage passageway extending therefrom, said cap being provided on the underside thereof with an annular groove connecting with said drainage passageway and having also a centrally disposed seat and an outlet passageway extending outwardly from said seat, a filter element extending across said recess, a receptacle depending from the cap, means detachably securing the receptacle to the cap comprising a flanged collar secured to the receptacle and having the upper edge thereof arranged to project within said groove, said collar and cap having cooperating locking elements for detachably securing said invention having been receptacle to said cap, a sealing ring supported by said flanged collar, a depending flexible filter bag within the receptacle having a rigid member provided with a conical surface engaging said seat, said member having a passage therethrough communicating with said outlet passageway, and spring means within the receptacle urging said member of the filter bag against said seat.

4. A sewing machine having an oil collecting sump, a cap connected with the bottom of the sump and having a drainage passageway therethrough communicating with said sump, said cap also having a seat and an outlet passageway extending outwardly from said seatthrough the cap, a receptacle communicating with said drainage passageway detachably secured to and depending from the cap, a flexible filter bag depending from said seat within the receptacle, a rigid member to which said filter bag is detachably connected, said member having a surface complementary to said seat and being provided with a passage therethrough communicating with said outlet passageway, spring means within the filter bag maintaining the filter bag in an expanded position, and spring means within said receptacle serving to urge said surface of said member against said seat.

5. A sewing machine having an oil collecting sump, a cap secured to the bottom of the sump and having a drainage passageway therethrough communicating with said sump and formed on the underside thereof with an annular groove communicating with said drainage passageway, said cap being formed also with a centrally disposed seat and an outlet passageway extending outwardly through said cap from said seat, a receptacle depending from the cap, means detachably securing the receptacle to the cap comprising a flanged collar secured to the receptacle and having the upper edge thereof arranged to project within said groove, said flange being formed with undercut locking surfaces, cooperating locking means on the cap, said receptacle being detachable from the cap by relative turning thereof to disengage said locking means from said locking surface, a sealing ring supported by said flanged collar arranged to eflect a tight seal between said receptacle and said cap, a depending flexible filter bag within the receptacle, a rigid member to which said bag is attached, said member engaging said seat and having a passage therethrough by which the interior of said bag communicates with said outlet passageway.

6. A sewing machine having an oil collecting sump, a cylindrical cap secured to the bottom of the sump and having formed therein a drainage passageway communicating with the sump and on the underside of the cap an annular grove communicating with said drainage passageway, said cap also having a centrally disposed seat and an outlet passageway leading from the seat, a receptacle depending from the cap communicating with said groove to collect oil from the drainage passageway, means detachably securing the receptacle to the cap, yielding means between portions of said cap and said receptacle to provide a tight seal therebetween, a filter bag depending within the receptacle, a seating element over which the upper end of the bag is fitted, a discharge tube supported from the seating element and providing an extension of the outlet passageway having the inlet opening thereof located within the filter bag adjacent its lower end, a yieldable filter bag expanding means within the filter bag, and a spring coiled about the filter bag and seating element serving to retain said bag on the seating element and acting between the receptacle and the seating element to maintain said seating element against the seat.

7. An overarm sewing machine having a base formed with a substantially fiat exterior bottom surface and partitioned to provide a return oil sump and a circulating oil reservoir in the base, a cap secured to the underside of the base in the region of the return sump, a depending receptacle and a filtering device within the receptacle depending from said cap, means for detachably connecting 7 said receptacle to said cap comprising complementary engageable and disengageable means fixed to said cap and receptacle, respectively, said filtering device being freed for removal upon detachment of said receptacle from said cap, said cap having a passageway through which oil is drained by gravity from said return sump into the receptacle and a second passageway through which oil is drawn through the filter device from said receptacle, a pump unit mounted on the base and extending through the same in the region of the circulating reservoir, and a pipe connecting said cap and the pump unit exteriorly of the base. r

8. A sewing machine having a circulatory oil system including a main reservoir and a return oil sump within said machine, said sump having the underside thereof apertured to receive an oil cleaning device, a cap secured to and substantially closing said aperture, a depending receptacle detachably secured to the cap, a filter bag extending from the cap into the receptacle, said cap having a drainage passageway from the sump leading into the receptacle externally of said bag and an outlet passageway from the interior of the filter bag, a filter element between the return sump and the drainage passageway for separating the larger and lighter solids from the oil passing therethrou'gh, an 'oil'pump carried by said machine connected with the outlet passageway for drawing oil through said cleaning deviceand delivering said oil to 5 said reservoir, and means operated from the machine for driving the pump.

References Cited in the file of this patent UNITED STATES PATENTS 2,014,105 Dooley Sept. 10, 1935 2,381,l41 Russell Aug. 7, 1945 2,392,666 Harris Jan. 8, 1946 2,502,346 Sauer Mar. 28, 1950 2,596,728 Sauer et al. May13, 1952 FOREIGN PATENTS 521,173 7 France Mar. 2, 1921 

